Heading for Shore

Tropical Atlantic sunset from the R/V Knorr -- March 2010. photo by G. Dwyer

We probably won't see another beautiful ocean sunset like this one for a while.

We're finished with our work here. All of our samples stored away for shipping and we're headed for dry land. On the way we've been cleaning the labs and our rooms, updating sample lists, filling out customs forms, calculating the weight of all of our samples (about 9000 metric tons!), and making sure all is well with the end-of-the-cruise to-do list.

Lead PI: Paul Baker, Duke University.

Its been a productive cruise. It was a long time coming, but it was worth the wait. I can't remember exactly when Paul first had the idea for this project. It was at least 6 or 8 years ago (maybe more). But, it finally became a possibility during our Fulbright sabbaticals in Brazil, in 2005. It was there that we meet and started to collaborate with our Brazilian colleagues. Pedro Tapia (of UFPA -- Universidade Federal do Para, in Belem) was our Fulbright host. He introduced us to many people during our 5 months in Brazil. And, importantly, although the Fulbright Federation sent us in the Amazon (yes, we developed projects and collaborations there as well), we managed to spend some time in Niteroi with Cleverson Silva (of UFF -- Universidade Federal Fluminense).

Collaborating Investigator: Cleverson Silva, UFF.

Cleverson, without whom this work in Brazil would not have been possible, introduced us to people from Petrobas, from the Brazilian Navy, and from other universities -- people who would prove to be very supportive of our research. His participation in this research brings valuable expertise in seismic stratigraphy, marine geology, and the geologic history of the Amazon fan, as well as much appreciated intellectual collaboration and commitment to the project's goals.

After several years of talking about it, thinking about it, developing hypotheses, worrying about logistics, and considering all of the other possible ways to test his hypotheses about the paleoclimate history of the Amazon Basin, Paul was finally ready to submit a proposal for this cruise.

PI: David Hollister, USF.

He realized immediately that this work would benefit from detailed studies of the biomass, hence needed a good organic geochemist on board. David Hollander, from the University of South Florida (USF) fit the bill perfectly. His expertise in marine biogechemistry, especially his work examining the terrestrial influx to marine systems was just what the project need. Paul was glad when Dave agreed to join the project as a PI.

Finally, Paul knew that the project would be greatly improved with his Duke colleague, Gary Dwyer, along to participate in the biostratigraphic studies and to take a lead in the foram/ostracod work that was needed to reconstruct paleo-SSTs and paleo-SSSs (sea-surface temperatures and sea surface salinities). With Gary signed on, Paul had his team assembled: PIs Baker (Duke) and Hollander (USF), co-PI Dwyer (Duke), and international collaborator Silva (UFF).

Co-PI: Gary Dwyer, Duke University.

It took a few attempts to get the proposal funded, but Paul did not give up. The proposal improved every time it was submitted. Also, the complexity of the logistical details became clearer and clearer with each passing day.

Fortunately, Cleverson was there all along, helping with site selection, providing geophysical data to support the project, and helping us handle all of the bureaucratic details that are necessary to do work in Brazilian waters (including heroically translating lengthy documents -- to and from Portuguese -- on very tight deadlines!). Importantly, he helped us obtain appropriate permissions from the Brazilian Navy and Brazilian Customs, and he introduced us to a new friend: Renato Rocha, our Brazilian Navy observer for the cruise.

Marinah do Brasil (our Brazilian Navy observer for the cruise): Renato Rocha.

Renato has been with us from the time we left Barbados. I'm not sure he is as excited about the geology as we are, but he is always upbeat and never far from the action. We're glad he was with us!

Excellent scientific research projects are rarely easy to put together. But, as with this one, they are usually worth the effort. Still, as good as this cruise has been, we're all excited to be heading to shore -- especially because "shore" in this case is Fortaleza, Brazil!

We'll have some work to do at dock (hauling core in preparation for shipping from Brazil to WHOI) before we can call it quits. But, we're all hoping to get at least an afternoon on the beach (aah . . . the Brazilian beach scene!) before heading back to the states.

Sea Salt

According to Wikipedia, "the word boatswain has been in the English language since approximately 1450. It is derived from late Old English batswegen, from bat (boat) concatenated with Old Norse sveinn (swain), meaning a young man, a follower, retainer or servant. The phonetic spelling bosun has been observed since 1868."

On oceanographic ships, the bos'n is the master of the deck. He (and very occasionally she) is in charge of all of the winches and lines and operations involved in launching and recovering equipment over the side of the vessel. The bos'n knows knots and rigging and shackles and winches and all kinds of other mariner stuff. On the Knorr, the bos'n, Pete Liarikos, is (and this is my opinion) the most ornery, salty, and cussedly lovable character on board. There is no harder worker, no tougher, and no better man on the ship. His loud, yes profane, outbursts only barely disguise his deep devotion to (and I suspect love for) his difficult work. Without Pete, we wouldn't have f'n noth'n.

Thank you Mates!

Captain Adam

It has been a real pleasure sailing these past few weeks with new friends and truly, able-bodied seamen.

On the helm, Master (Captain) Adam Seamons, First Mate Dee Emrich, Second Mate Derrick Bergeron, and Third Mate Alison Paz have been great to work with. Unlike officers on a merchant vessel who drive ships from point a to point b and back and so on, officers on the Knorr and other oceanographic vessels, have to undertake a far greater variety of missions.

Thus, in addition to driving the vessel, they have to oversee many aspects of the oceanographic operations. And they sometimes have to remind us crazy oceanographers that we are asking for
something unreasonable or unsafe or impossible.

Every crew member on the ship has multiple tasks that are their responsibility and it is the same for the officers.

It is not unusual to see Alison with a hose in her hand rinsing off one of the skiffs, to see Derrick planning navigation for the next leg of the vessel (to Capetown), to see Dee checking the safety gear on board, or to see the Captain plowing through mounds of paperwork. Their jobs are certainly not pure glamour.

But they can be sure that we greatly appreciate all they have done for us.

1st Mate Dee

2nd Mate Derrick

3rd Mate, Allison

Wildlife of the Day (Episode 4)

I thought I was seeing a piece of plastic trash in the sea this morning -- my first on this cruise. Fortunately, I was wrong.

Upon closer inspection, it was one of these:

Anyone who has accidentally brushed up against the tentacle of one of a Portuguese Man o' War already knows more than s/he wants to about this animal -- and does her/his best to avoid them at any cost.

Portuguese Man o' War (the scientific name is Physalia physalis) are common in warm waters around the world. And, though they are often called jellyfish, they are actually colonial hydrozoans -- they are made up of a large colony of smaller organisms.

A Dutch man-of-war firing a salute. (image from http://hamrunscouts.com/info/wp-content/uploads/2009/05/portjell.gif).

In my experience, where there is one man-of-war, there are usually more. This is because the man-of-war's large, blue, gas-filled bladder floats above the water's surface and serves as a sail for the colony. This means that with the right wind large numbers of man-of-wars (or is it men-of-war?!) can be blown into the same area -- sometimes they are found in flotillas (rafts) of hundreds.

But not today. Today I saw only one.

It was a pretty sight, but I was glad to be on the ship rather than in the water. Although the sting of the Portuguese Man o' War is not deadly to humans, it is very painful and often comes in multiples.

Maybe this is another reason for the name. Not only does this organism's blue "sail" resemble the triangular sail of the 15th and 16th century warship, its fires a heck of a shot!

What's an SSSG?

SSSG stands for Shipboard Scientific Services Group.

The SSSGs are the shipboard technicians who keep everything related to the scientific mission of the cruise running smoothly.

The three major vessels in the fleet normally have an SSSG technician assigned to all cruises. The two largest ships (the R/V Knorr and the R/V Atlantis) have 2 technicians on each cruise. This means that on these two vessels, there is 24 hour technical assistance available to help make sure the scientific operation runs smoothly. What luck!

SSSGs Amy Simoneau and Robbie Laird.

Our 2 cruise SSSGs are Amy Simoneau and Robbie Laird. And, we are lucky on this cruise to have a third technical support person -- Peter Lemmond, who is here as the at-sea SeaBeam support person.

SeaBeam Technician Peter Lemmond.

Amy and Robbie are responsible for making sure the ship's data collection systems are working correctly and for the logging and data distribution systems (this means all of the sensors, computers, display devices, cabling -- everything that records data onboard the ship).

They also maintain, calibrate, prepare and operate (and teach us how to operate!) all of the general-use research equipment onboard the ship -- everything from the over-the-side instrumentation (like the CTD and box core) to the Chirp and ACDP systems to the printers and plotters. Plus, they maintain the ship's computer system -- including the internet connection that allows this blog to exist!

Finally (well, not really -- they do so much it is difficult to list it all here!), the SSSGs also serve as the scientific interface with the crew in many operations, assisting the Boatswain and other crew members as needed. They make sure the scientists do what they are supposed to do when it comes to operating instruments and staying safe.

In short, Amy and Robbie make sure that everything is working properly so the scientists can go about their research without too many glitches. And, when glitches do happen (like when the printers don't work, or the Chirp system is not recording properly, or the internet goes down), Amy and Robbie are there to set things straight. (Assuming of course, that we didn't crash the internet by forgetting that we are at sea and do have to be careful with bandwidth!)

Amy to the rescue!

So, how does one get to be an SSSG? Amy tells me that she was once thinking about continuing on for her Ph.D. and becoming a research scientist. The only problem was that she was interested in too many things! She liked being involved in many different kinds of projects on many different topics. She also liked the idea of traveling the world and meeting lots of different people. Plus, as we found out quickly at the beginning of the cruise, she has a gift for making things work. Her interest in all things scientific, her great hands-on technical ability, and her can-do (and will do!) attitude seem like perfect characteristics for an SSSG. They sure work for Amy (and for us)!

Today, Amy and Robbie and Peter ar busy preparing for our arrival in port. They are preparing final data files for the PIs to take home with them, helping us put the labs back into shape for the next cruise and pack the containers that hold all of our samples (and some of our instrumentation), and generally getting us ready to leave the ship with everything we need to continue this research.

Without our SSSGs, we would have a very hard time out here!

So, thanks Amy, Robbie, and Peter. You've really helped make our cruise a success.

Squeeze Anyone?

We're getting our last long core today. Yes, the cruise is almost over. We've got plenty of mud -- enough, in fact, to keep us occupied for a long while!

One of the people who will be very occupied with all of this mud is Trevor Nace. Trevor's Ph.D. dissertation will be based, in large part, on the data collected on this cruise. He will be analyzing the cores with the aim of reconstructing the paleoclimatology and paleooceanography of this region.

Trevor will do the foram stratigraphy, will analyze 18O isotopes in the pore waters, and will do Mg/Ca, Ba/Ca, and oxygen isotope analyses on the forams to reconstruct sea surface temperatures and sea surface salinities. He will use the data from these analyses, in combination with organic geochemical studies of the terrestrial component of the core material, to get a long (~30,000 years) paleoclimate record. Sounds like a great project!

Trevor has already started some of the hard work. While on the cruise, he has spent a lot of time in the wet lab (just forward of the main science lab). He's been squeezing porewater. That is, he's been putting mud from the long cores into a press and, literally, squeezing the water out of it.

Here's how it goes:

Trevor scoops mud from the end of the long core sections,

places the mud in a stainless steel vessel, and uses a jack-like device to squeeze it.

Then, he patiently waits (sometimes for a half hour or more) for the syringe he has put into a hole in the bottom of the vessel to fill up with pore water. Sometimes a little extra squeezing (with the jack) is required.

Once the syringe is full, he removes it from the contraption and ejects the pore water into a bottle.

This is the kind of thing that must be done on the ship -- before the cores dry out and the pore water is lost.

All of the bottles will be shipped back to the lab at Duke, where Trevor will do oxygen isotope analyses on the pore water he squeezed while on board the Knorr -- hoping to get a set of data that will prove useful in his paleoclimate reconstruction.

A Beautiful Channel

Today our survey took us over this lovely, meandering submarine channel:

SeaBeam image of a portion of a submarine channel off the coast of Sao Luis, Brazil

It is one of several channels at the distal end of a small lobe of a submarine fan that is located offshore of Sao Luis, Brazil. The channel is probably ultimately fed by the rivers that drain the province of Maranhao (the Grajau, Pindare, Mearim, and others) and that empty into the Atlantic Ocean near Sao Luis.

The submarine fan in this area is nowhere near the same scale as that of the Amazon fan. Still, this channel seems worthy of note -- at least to a sedimentologist like me, who loves rivers! After all, this channel may be under a couple thousand meters of water, but it has meanders, it channels water down slope, and is in many ways similar to continent-bound rivers. Sort of . . .

Notice, for example, the narrow ridges that line the channel. These ridges are levees. They are produced by overbank flow (flow that is too large to be confined to the channel, hence spills out over the top and onto the surrounding surfaces), just like levees in river systems on land.

Also notice the large, curved, slump features on the right side of the channel (in the green/blue shaded area). Although slumping does occur on the cutbanks of rivers on dry land, it is even more common in submarine channels, where all of the sediments are saturated with water.

We don't know how old this features is, but we cored close to it so we may be able to determine its age when we analyze the sediments. In any case, it really is a beautiful feature.

Isn't geology fun?!

Hugh's Release

The long piston corer has enabled us to recover several amazing geological records. Of course, we won't know the details until we finish literally years of laboratory analysis. But for now we can state categorically that there is no other piston coring tool that can be deployed from a US oceanographic ship that produces such a long and high quality sediment core. While it was previously ordinary to recover 10 m long piston cores and occasionally up to 20 m of mud, the CDH has rather routinely allowed us to recover over 30 m of sediment. This increased length of cored sediment, of course, increases the amount of geological time recorded by the sediment. This innovation was only made possible by the vision, knowledge, and stubbornness of Jim Broda, Senior Research Specialist at WHOI. If you have followed the blog, you know all of this already.

But, last night we had an event that demonstrated that using the CDH is not "routine." For the second time on the cruise we had a failure to release: after two hours descending on a winch to 3500 m water depth, the corer did not respond to the signal transmitted from the ship. What to do?

After two hours of recovery, another few hours for repair with rubber bands (really) (and more), then back to the seafloor. Again, no communication. Another failure.

We were looking at the possibility that we would not be able to recover what looked (in the seismic record) to be some of the best sediments on the whole expedition.

A 3.5 KHz seismic reflection profile image of the
sediments in the upper 30 meters below the seafloor.
These sediments are stratified and a bit folded,
probably due to slumping. Our long core samples
almost all of this section.

The old release mechanism, including rubber bands.

Instead, Hugh Popenoe (whose father is a well known marine geologist) and Tito Collasius, working throughout the night, undertook a complete reconfiguration of the release mechanism, eliminating the above solenoid, release mechanism, and rubber bands.

Hugh tries out his new release mechanism. Professor
Cleverson Silva, from UFF, Niteroi, Brasil, stands
by (he is another big time hero, but that is another story).

Tito (left) and Jim check out their retrofit in first light.

Thirty-six hours after arriving at the station, we recover a beautiful, 30 m long core. I've been involved in a lot of field work through the years, enough to say with some authority that this was a major league, prime time save. All for science!

The Scribe

"Ah, who is the scribe?" You ask. This fantastic blog has been kept alive by Professor Catherine Rigsby. She has solicited and elicited some help from the rest of us sloths, but Catherine has written most of the interesting and entertaining entries about our expedition. At the same time, among many other tasks, Catherine has undertaken the heroic effort of cataloging every sample taken aboard the ship. Every time we take a core, every time we sub-sample a core, every time we take a water sample, etc., Catherine makes an entry in the cruise spreadsheet. As you can see, this work has been a real pain in the neck:

Long lists of samples such as this:

are needed for our scientific work and, more immediately, for sample clearance by the Brazilian Departamento Nacional de Produçao Mineral and Brazilian Customs.

Thank you Catherine!!

Studying past and present

Reconstructing the climate and hydrology of the Amazon basin from 30,000 years ago to the present, finding out if vegetation in the Amazon changed as climate changed, and trying to determine how changes in Atlantic sea-surface temperature (SST) may have had a role in causing these changes are the main goals of the research associated with this cruise.

Because we're trying to understand the link between the ocean and the continent, we're examining many different types of samples and using a combination of methods (including inorganic and organic geochemical methods) to reach our study goals. This combination of sample types and methods will allow us to study not just the mud and sand transported into the ocean by the Amazon River, but also the plant and animal debris (the terrestrial biomass) that is transported in the Amazon outflow.

All of our study methods require both abundant material from gravity cores and the long cores (so that we can reconstruct the record of a long period of geologic time) and a good understanding of the modern environment in this region.

As a primary tenet of geology is often stated, "the present is the key to the past." In the context of research like this, this statement means that we study the characteristics and processes of the modern environment in order to understand both the processes that are likely to have operated in the past and the probable characteristics of the sediments that were produced by those processes.

An understanding of modern processes helps us make interpretations about past environments. This is one reason we need so much young, near-the-seafloor sediment -- so that we can learn more about the modern system and use that knowledge when we interpret the sediments that were deposited in the past.

The multicorer -- on the deck and ready to be deployed.

Enter the multicorer.

The multicorer can collect 8 short cores in a single deployment, making it an effective way to get lots of seafloor and shallow sub-bottom sediments in one deployment -- just what we need when trying to do so many different kinds of analyses.

It is a relatively simple tool to use and, with a little know-how, it is easy to extract multiple high-resolution samples from the individual cores. Andy Nunnery (one of the Duke PhD students on this cruise) has been doing just that.

Here's how he does it.

First, the individual cores are removed from the tripod and
hung on a wall-mounted rack.

The cores are measured and then removed from the rack and put into a core extrusion device. (The photo on the right shows the device without a core in place.)

The core is slowly pushed up through the its own core tube (by pushing up on the the white, plunger-like device) and samples are sliced off the top, typically in 1 or 2 cm slices (the photo on the left shows a core in the extraction device).

Because he is taking these samples for foram analysis, Andy treats each sample with formalin (which dyes the organic matter so it is easy to identify later) before placing it in a jar for storage and shipment back to the lab at Duke.

It's as easy as that.

Except, now all of the samples must be transported home and analyzed. The cruise, the cores, and all this sampling is only the beginning or this project!

Tony's Tuna

What a catch! Tony Skinner, the Knorr's Communications Officer, caught this bluefin tuna early this morning.

He said it took out almost all of his line, but it only took him about 30 minutes to bring it in. Boy was Paul impressed! (So are the rest of us, of course.)

I don't know, but my guess is that Tony has some experience at this sort of thing. He hails from Hawaii, where his relatives immigrated from Puerto Rico in the early 1900s.

Did you know that there are over 25,000 Puerto Rican-Hawaiians in our 50th state (Hawaii became a state in 1959)? Neither did I.

Immigrants first came to Hawaii from Puerto Rico after Puerto Rico was devastated by two major hurricanes in 1899. Hurricane San Circiaco, a category 4 storm, hit in early August. It had winds over 100 mph and was followed -- only 14 days later -- by another, unnamed storm. The result was over 3000 deaths, thousands of people left without homes or food, rain and flooding that lasted almost a month, and sugar and coffee plantations in ruins. Owners of sugar cane plantations in Hawaii immediately began to recruit experienced laborers from Puerto Rico.

Tony's relatives traveled to Maui on a ship like this one.

Tony's great grandparents were part of this first wave of Puerto Rican immigrants. They arrived in Hawaii on December 23, 1900, onboard the steamship Rio de Janeiro, having set sail from San Juan on November 22nd. They first lived on the island of Maui, where they worked on a plantation called Paella. Tony says his relatives still attend reunions of the families of the people who worked and lived together during those years.

Apparently, it was not easy going for the early immigrants. Puerto Ricans worked and lived among many other immigrants to Hawaii. From the late 1800s until the mid 1900s almost 400,000 people were brought to Hawaii to work on the sugar plantations. They came from China, Japan, the Philippines, Korea, Portugal, Samoa, Norway, Germany, Spain, India, and Russia (among others). Many of them returned to their homelands. But may stayed, making Hawaii a true multi-ethnic melting pot. Unfortunately, the plantation owners discriminated based on ethnicity and race, giving European immigrants better pay and better living quarters than that of their co-workers. This treatment resulted in much interethnic strife among the various immigrant groups.

When President Wilson signed the Jones Act in 1917 Puerto Rico became a territory of the US and Puerto Ricans became US citizens. The territory of Hawaii, however, refused to recognize that citizenship for the plantation workers. A lengthy court battle ensued. Finally, the territory was forced to recognize their citizenship, giving the immigrants a new, legal home and the rights and status they deserved.

Tony's family eventually moved to Oahu, where Tony still lives (when he's not living on the ship, that is). But the family history has not been forgotten.

Tony has been working on ships, creating more family history, for a long time now. In process he's managed to travel the world. On his way home from this cruise, he plans to stop off in France for a visit with his teenage son.

Thanks Tony for teaching us a bit about the history of Hawaii and, of course, for providing a great fish for dinner. We do get to eat it for dinner, don't we?!

Wildlife of the Day (Episode 3)

Pteropod shells Hugh retrieved from tonight's box core.

We've found shells like these on the surface of almost every one of our box cores on this cruise. Hugh picked these out of tonight's box core and wanted to know about them. I hope this answers his questions.

They are pteropods -- little marine crustaceans with translucent shells that are also known as a sea butterflies or flapping snails.

These planktonic gastropods (snails) are found in all oceans, from the Arctic to the tropics. They spend their lives floating and swimming, and can being carried along in ocean currents.

The name pteropod is an old one, but it is still commonly used. In Greek, pteros means "wing" and podos means "foot," making the old word an excellent description for this animal that swims by using two wing-like appendages.

Pteropod shells are made of aragonite. They are thin and delicate, and are easily dissolved in the deep ocean. In the Atlantic, the aragonite compensation depth (the ACD -- the depth at which mineral aragonite dissolves) various with location, but is generally between 2000 to 3000 meters. This core was taken at a depth of 2372 m -- obviously above the local ACD.

Most pteropods live in the upper 500 m of tropical and subtropical waters. They are nocturnal filter-feeders, descending to deeper water in the daylight hours and rising to the surface waters at night to feed on microscopic organisms.

Here's a little know fact: pteropods start life as males and then become females. Interesting . . .


Living pteropods

Long Coring -- in pictures

We tried to get another long core last night, but had a slight glitch -- a mechanical glitch that prevented releasing the core at the bottom. No problem. Early on we noted that flexibility is required in this business. We decided to continue our survey while the glitch got fixed and we're are now looking at another potential coring site.

There is a lot of interest in (and more than a few questions about) the long coring operation, so I decided to post this pictorial essay of the long core operation. I've included a few figure captions to lead the way. As a start, the diagram to the right illustrates the basic set-up: the long core is first lowered to vertical, then moved to the back of the ship for deployment.

Thanks go to Cleverson and Gary for most of the photos that follow.

When not in use, the long core rests (and is rested upon) on its perch along the starboard railing.

Before coring can commence, the 3-meter-long pieces of liner are pre-marked (section one is the bottom -- deepest-- section) and then inserted into the core barrel.

The corer is carefully lifted off its perch . . .

. . . and lowered into a vertical position at the stern of the ship.

Once at the vertical, the corer is repositioned to the center stern of the ship.

The corer will be attached to the "dog dish" and lowered via a cable that is fed through this slot in the stern deck.

The next series of photos show this happening.

Done!

Now we move inside to watch the action on the monitor. The scientists join in this fun too. All eyes are on the wench tension.

Once the corer reaches the bottom it is "released" and plows through the seafloor, picking up sediment as it goes. It is then brought back on board, placed in its perch on the starboard railing, and extruded.

The core is extruded (pushed from the top by the folks in the "man basket" that hangs out behind the ship); the liner sections are separated, cleaned, and capped;

and the sections are brought into the main lab, where they degasses as they await logging.

If you want to see the long coring operation in even more detail (and with action), check out the long coring video on the WHOI website (also available in a QuickTime version).